Development and psychometric validation of the Italian version of the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS)

• Italian WRAADDS was developed and validated for assessing adult ADHD. • Excellent inter-rater reliability ( r ≥ 0.815) and internal consistency (α ≥ 0.88). • Good concurrent validity with measures of ADHD and emotional dysregulation. • ADHD was identified with 88 % accuracy, 92 % sensitivity, 84 % specificity. In this study we developed and validated the Italian version of the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS), a clinician-rated scale for attention-deficit/hyperactivity disorder (ADHD) in adults. It assesses both observable behavior and subjective experiences and is tailored to address clinical features more directly relevant to adults with the disorder. 50 participants were recruited, including 32 referred to the Psychiatry Unit 2 at Pisa University Hospital, and 18 recruited through snowball sampling. 25 were diagnosed with ADHD, 15 with other psychiatric conditions, and 10 were healthy controls. All participants were evaluated using the WRAADDS and a set of clinician-rated, informant-rated and self-rated instruments. Psychometric characteristics of the WRAADDS were assessed, including inter-rater reliability and internal consistency, as well as concurrent and criterion validity. The WRAADDS total and composite domains score showed excellent inter-rater reliability (Spearman's r ≥ 0.815; N = 17) and internal consistency (Cronbach's α ≥ 0.88). Concurrent validity was supported by correlations with measures of inattention, hyperactivity/impulsivity, and emotional dysregulation ( r ≥ 0.6). Patients with ADHD scored significantly higher than the other participants on several WRAADDS scores and an ADHD composite score ≥ 8 distinguished patients with ADHD with accuracy = 88 %, sensitivity = 92 %, and specificity = 84 %. In conclusion, the Italian version of the WRAADDS is a valid assessment tool for adult ADHD, facilitating a comprehensive understanding of the disorder within the adult population.